title: Synthesis of the 6-deoxytalose-containing tetrasaccharide of the glycopeptidolipid from Mycobacterium intracellare serotype 7.
abstract: An efficient synthesis of 4-methoxyphenyl alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->2)-6-deoxy-alpha-L-Talp, the tetrasaccharide related to the GPLs of Mycobacterium intracellare serotype 7, was achieved with 4-methoxyphenyl 3,4-di-O-benzoyl-6-deoxy-alpha-L-talopyranoside (6c) as the key intermediate which was obtained through selective 3-O-benzoylation of 4-O-benzoyl-6-deoxy-alpha-L-taloside. Coupling of 6c with 3-O-allyloxycarbonyl-2,4-di-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate followed by removal of the allyloxycarbonyl protecting group afforded the disaccharide acceptor 11. Condensation of 11 with 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->3)-2,4-di-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate and subsequent deprotection gave the target tetrasaccharide.
authors.affiliation: Key Lab of Pesticide Chemistry and Application Technology, Department of Applied Chemistry, China Agricultural University, Beijing 100094, China.
authors.forename: Shiqiang
authors.initials: S
authors.lastname: Yan
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Liang
authors.forename: Peiyu
authors.initials: P
authors.lastname: Diao
authors.forename: Ye
authors.initials: Y
authors.lastname: Yang
authors.forename: Jianjun
authors.initials: J
authors.lastname: Zhang
authors.forename: Daoquan
authors.initials: D
authors.lastname: Wang
authors.forename: Fanzuo
authors.initials: F
authors.lastname: Kong
mesh_terms: D000215:Acylation; D002240:Carbohydrate Sequence; D003837:Deoxy Sugars / Q000737:chemistry*; D006017:Glycolipids / Q000737:chemistry*; D006601:Hexoses / Q000737:chemistry*; D008969:Molecular Sequence Data; D015269:Mycobacterium avium Complex / Q000737:chemistry*; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: D003837:Deoxy Sugars; D006017:Glycolipids; D006601:Hexoses; D009844:Oligosaccharides; C011754:6-deoxytalose